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300 PRC update

my barrel has about 250 rounds in it now,
I see some velocity changes.
I had a node @771.-77.4 from 2800-2809fps
another one 78.3-78.9 2855-2864fps when the barrel had 160 rounds on it

now looks like at 77.1-77.4 I have 2839,2845,2848,2856fps(0.1grs increaments) and 77.4 gives me the ES:4, SD:2.3

it shoots under .3 MOA but the problem is that I don't have that .3grs window anymore.

should I do another ladder test?
 
I am losing my mind😂
the velocity is reducing with every 100 rds with the same charge weight
Last range trip about 30-40fps
Barrel was cleaned the same way, this time I even uses 3 wet patches of CLR follwing by 3 patches of %91 alcohol and then boretech c4 and then boretech copper remover, and the. A few patches of jb, anyway the same way I clean everytime. The same lot of powder and primer. This time i used super trickler!
Why the heck i am getting lower velocity.
4x fired lapua brass, Below is the ladder test from last evening

The confusing part is that looks like the powder node stays close to where it was even with lower velocity
Like 77.1-77.4 @ 2789-2800
Then 77.1-77.3 @ 2774-2777
Then 77.5-77.7@ 2760-2749
Seating depth is increased to compensate the 20thou distance to the lands by 30thou from the first test to the last test
IMG_9648.jpeg


IMG_9649.jpeg



Right now my node with the lowest sd/es is 77.5-77.6 with just under 0.5 moa and 2756 fps
the barrel has 500 Rds count at the end of this test
 
Looks like I was able to score. A few pounds of H1000 from powder valley today
I might give that a try as well
 
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Hi all… I am ready to step onto the world of high powered magnum rifles….
Lightweight hunting rifle is ideal for me right now. Not sure if I want a custom action or pick up a proof 300prc prebuilt or seekins?

only drawback I see is the limited types of powder for the heavy 200+ grain bullets

During the absolute primer heist, everybody locally was out cutting online with inflated prices. Not sure how competition guys got their primers , but Scheels had them in stock when no one else did.
So that’s why I give Scheels outfitters props.
 

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Kocher said:
Hi all… I am ready to step onto the world of high powered magnum rifles….
Lightweight hunting rifle is ideal for me right now. Not sure if I want a custom action or pick up a proof 300prc prebuilt or seekins?

only drawback I see is the limited types of powder for the heavy 200+ grain bullets

During the absolute primer heist, everybody locally was out cutting online with inflated prices. Not sure how competition guys got their primers , but Scheels had them in stock when no one else did.
So that’s why I give Scheels outfitters props.
Click to expand...
This quantity of brass should be enough for 3 barrels lol
 
category_theory said:
Gotcha….. I mean I had some issues but moved over to Redding S Match dies and they seem to work great…. 🤷🏻‍♂️
Click to expand...
information could not have come at a better time as I’m looking to buy dies next if we compiled a list of 300 PRC dies that resize the 300prc brass case to Sami spec or at least enough to prevent a stiffy lift:
1-Reading S match died?
2- small company that custom-makes the die?
And no others?

will be doing a fair share of shooting and I’m guessing I will reload my cases more than six times..
 
Max_The_Phoenix said:
This quantity of brass should be enough for 3 barrels lol
Click to expand...
How many times can you typically reload the 300prc Lappula brass?
Obviously not all things equal but with relative conservative pressures. ( i’d like to have a mid range node as far as powder loads, but beggars can’t be choosers.
 
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Kocher said:
How many times can you typically reload the 300prc Lappula brass?
Obviously not all things equal but with relative conservative pressures. ( i’d like to have a mid range node as far as powder loads, but beggars can’t be choosers.
Click to expand...
I already have 6 reloads on my brass and the primer pockets are tight, I don’t see I should be able to get 10-12 reloads on them. Make sure you don’t run them hot for the fireforming
 
Kocher said:
How many times can you typically reload the 300prc Lappula brass?
Obviously not all things equal but with relative conservative pressures. ( i’d like to have a mid range node as far as powder loads, but beggars can’t be choosers.
Click to expand...
Do you anneal every firing?
 
Kocher said:
Hi all… I am ready to step onto the world of high powered magnum rifles….
Lightweight hunting rifle is ideal for me right now. Not sure if I want a custom action or pick up a proof 300prc prebuilt or seekins?

only drawback I see is the limited types of powder for the heavy 200+ grain bullets

During the absolute primer heist, everybody locally was out cutting online with inflated prices. Not sure how competition guys got their primers , but Scheels had them in stock when no one else did.
So that’s why I give Scheels outfitters props.
Click to expand...
Limited powders? Huh? N560, 568, 570, Retumbo, H1000, 4831sc, Ramshot Mag, RL26, take your pick!
 
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Max_The_Phoenix said:
my barrel has about 250 rounds in it now,
I see some velocity changes.
I had a node @771.-77.4 from 2800-2809fps
another one 78.3-78.9 2855-2864fps when the barrel had 160 rounds on it

now looks like at 77.1-77.4 I have 2839,2845,2848,2856fps(0.1grs increaments) and 77.4 gives me the ES:4, SD:2.3

it shoots under .3 MOA but the problem is that I don't have that .3grs window anymore.

should I do another ladder test?
Click to expand...

Unfortunately this is a fundamental misunderstanding of how things work. Both the physical and the mathematical aspects.

There are no such things as velocity flat spots or "nodes" when we are talking chronograph numbers. I'm not talking about POI on paper at various distances.....that's an entirely different topic. It's basically impossible to go from 77.1-77.4 and only have a few FPS difference. What you're seeing in small sample size "ladder" tests is random dispersion through the ES of a powder charge that happens to overlap.

I.E. 77.1 was on the high end of the ES and 77.4 was on the low end of ES. So they give the illusion there was a "flat spot" or "node." As you can see when you ran it again and got a velocity dispersion that is more realistic. This time, your sample size didn't overlap. I think you can see where I'm going with that.

The other misunderstanding is with ES and SD. If you have an SD of 2.3, you will have an ES of over 10fps 95% of the time. So that 4es really means nothing. And you wouldn't have listed it if you understood that (I'm assuming, I apologize if incorrect). Also, you'd need to extrapolate that 2.3 SD with the amount of shots fired in the sample size and a 95% confidence interval. Which would then give you a realistic range (you'll never know your true SD (and by default, also your true ES) without many, many rounds fired. So, we need to extrapolate the sample SD to a realistic range. That allows us to objectively compare different load data and determine which are noticeably better or worse than the others. And then which ones are likely around the same as others.



The TLDR: no, don't do another velocity ladder. It's a waste of components/time with no objective reality.

With that low of an SD, even if just 5rnds, it's very likely that your true SD is under 7fps, which is a very good place to be. If it was only 3rnds, then you're very likely to be under 15fps, with something like a 66% chance that you're under 10fps. Regardless, 2.3fps even in a small sample is indicative of a likely good load.
 
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Rio Precision Gunworks said:
Unfortunately this is a fundamental misunderstanding of how things work. Both the physical and the mathematical aspects.

There are no such things as velocity flat spots or "nodes" when we are talking chronograph numbers. I'm not talking about POI on paper at various distances.....that's an entirely different topic. It's basically impossible to go from 77.1-77.4 and only have a few FPS difference. What you're seeing in small sample size "ladder" tests is random dispersion through the ES of a powder charge that happens to overlap.

I.E. 77.1 was on the high end of the ES and 77.4 was on the low end of ES. So they give the illusion there was a "flat spot" or "node." As you can see when you ran it again and got a velocity dispersion that is more realistic. This time, your sample size didn't overlap. I think you can see where I'm going with that.

The other misunderstanding is with ES and SD. If you have an SD of 2.3, you will have an ES of over 10fps 95% of the time. So that 4es really means nothing. And you wouldn't have listed it if you understood that (I'm assuming, I apologize if incorrect). Also, you'd need to extrapolate that 2.3 SD with the amount of shots fired in the sample size and a 95% confidence interval. Which would then give you a realistic range (you'll never know your true SD (and by default, also your true ES) without many, many rounds fired. So, we need to extrapolate the sample SD to a realistic range. That allows us to objectively compare different load data and determine which are noticeably better or worse than the others. And then which ones are likely around the same as others.



The TLDR: no, don't do another velocity ladder. It's a waste of components/time with no objective reality.

With that low of an SD, even if just 5rnds, it's very likely that your true SD is under 7fps, which is a very good place to be. If it was only 3rnds, then you're very likely to be under 15fps, with something like a 66% chance that you're under 10fps. Regardless, 2.3fps even in a small sample is indicative of a likely good load.
Click to expand...
Thank you for taking the time to write this up.
have a question: you just pick a load with low SD/ES and adjust your seating depth?
What happens when temperatures are higher?
 
Max_The_Phoenix said:
Thank you for taking the time to write this up.
have a question: you just pick a load with low SD/ES and adjust your seating depth?
What happens when temperatures are higher?
Click to expand...
Your density altitude will change which usually changes velocity/dope. It can change enough to cause a larger group. However if you can tune the load to stay closer to the velocity the barrel wants to shoot at by reducing the charge or increasing the charge with enough change in temp. You also do not want a round in a hot barrel for any longer than it takes to acquire and shoot.
 
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Kocher said:
well it is odd... but these powders have actually showed up (been a long time ).,... perhaps our oppressors did not get all of it for mortar and artillery shells?...

So how IS H1000 with TEMP swings?
Click to expand...
Yeah I enabled all my email notifications to get these powders
I shot H1000 in my friend’s 6.5 PRC but he was pretty happy with it and says it’s very consistent.
Been shooting Retumbo in the past few months with my 300 PRC, I will get my new barrel next week So I can start playing with H1000 and will report here
 
Kocher said:
well it is odd... but these powders have actually showed up (been a long time ).,... perhaps our oppressors did not get all of it for mortar and artillery shells?...

So how IS H1000 with TEMP swings?
Click to expand...
I shoot H1000 w 220 LRHT… running about 78gr from a 30” barrel and getting 2940 w single digit SDs in the 3-4 range…. And that’s from 30 shots. N570 w 245 LRHT also gives amazing results w similar speeds.
 
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category_theory said:
I shoot H1000 w 220 LRHT… running about 78gr from a 30” barrel and getting 2940 w single digit SDs in the 3-4 range…. And that’s from 30 shots. N570 w 245 LRHT also gives amazing results w similar speeds.
Click to expand...
Wow that’s amazing
How is the throat erosion?
 
Kocher said:
So how IS H1000 with TEMP swings?
Click to expand...
I run Retumbo, which is excellent in this regard. H1000 should be very similar, since it is also in the same Hodgdon "Extreme" line as Retumbo, Varget, H4350, etc, which means stable in "extreme" temps.
 
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Since my new 30" Proof barrel sped up after 170 rounds I am getting an average speed of 3015 with 5-6 SD's with 78.5 grains of H1000 and Berger 220 LRHT's.
 
338LM said:
Since my new 30" Proof barrel sped up after 170 rounds I am getting an average speed of 3015 with 5-6 SD's with 78.5 grains of H1000 and Berger 220 LRHT's.
Click to expand...
Damn! May have to pump up my loads a bit. What brass are you running? I’m running Lapua w a little bit of compression.
 
I am using Lapua brass.
Chamber and throat SAAMI.
3.750" OAL to the barrel lands approx. (actually measuring with comparator over ogive).
Seat .030" off the lands at 3.720" OAL approx. (actually measuring with comparator over ogive).
 
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Well, for now, I think I’m going to bow out… I don’t have my other components (barrel , stock , trigger ,action) or if I go the commercial way (a rifle). Will have to clear out inventory and organize it.. sell a rifle then have money to get the said shove.. do not want to go into debt for something I don’t need right now ( 6.5 cm or 22CM or 6cm will work well for most light to mid sized game anyway.)

I can use those powders in my 22 CM. For heavies but… at 424$ to my door for 8 lbs I am going to have to wait…. I have plenty reloading components for other calibers and not having yet another item laying around that could ignite
in my house…. Fires are fucking real… and primers/powder goes up fast and hot.
I may make some wood containers to store the stuff in and then perhaps use metal on the outside. I don’t know I just don’t want these fucking things to be kinder boxes.

One retailer online will only allow one 8lb at a time.. found some local and of course they add on 35$ more…. I think we are in a recession and prices are going to come down because people are not going to keep buying $1000 for a couple 8 pound jugs of powder and 3000 sr primers every couple months.

It’s hard, because I know our government is working hard against law abiding gun owners from restriction of ammunition to powders to primers to whatever else there trying to come up with..
isn’t it time we start organizing with like minded folk.
 
Also, sorry to rant, but I have not seen any large rifle magnum primers call across the table in quite some time perhaps over a year already…. Again, not sure where guys are getting theirs but no wonder why the large rifle primer brass is sitting on the shelves
 
Kocher said:
Also, sorry to rant, but I have not seen any large rifle magnum primers call across the table in quite some time perhaps over a year already…. Again, not sure where guys are getting theirs but no wonder why the large rifle primer brass is sitting on the shelves
Click to expand...

You don't necessarily need magnum primers. I haven't shot my 300 PRC with such in years. I found slightly better results with BR-2s and haven't switched since.

Now, I don't shoot in cold weather, but I'm spoiled... I don't need to. Coldest I've shot in is high 30s, but the BR-2s worked fine there.
 
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I have never shot magnum primers in my 300 PRC. I have shot down to 30° with Federal and CCI standard and match primers without any issues.
 
Rocketmandb said:
You don't necessarily need magnum primers. I haven't shot my 300 PRC with such in years. I found slightly better results with BR-2s and haven't switched since.

Now, I don't shoot in cold weather, but I'm spoiled... I don't need to.
Click to expand...

I have had hang fires with ball powder and sr primers with 6.5 CM. In winter months.. but this powder is stick/extruded so should be dif. Perhaps fare better within the cold… extreme powders usually fair better. I noticed that all of the extreme powders are Extruded!

Thank you for the info about the primer's!
 
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Max_The_Phoenix said:
How far do you want to shoot?
Click to expand...
And how much pain you want to endure.
And how deep your wallet is.

I was at a shoot this weekend and a guy was shooting a 375 Chey Tac. I think he said that even reloading it cost him $6 or more per round. The concussion would make you say WTF?

But he was nailing a mile with ease.
 
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Maggot said:
And how much pain you want to endure.
And how deep your wallet is.

I was at a shoot this weekend and a guy was shooting a 375 Chey Tac. I think he said that even reloading it cost him $6 or more per round. The concussion would make you say WTF?

But he was nailing a mile with ease.
Click to expand...
Yep
Before choosing 300 PRC I did lots of research regarding the cost of powder, bullet, barrel life,etc. looks like at this cost it’s one of the best long range cartridges in the market
 
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Maggot said:
Literally a "Best Bang for your Buck".
Click to expand...
No totally! That’s why I’m also sticking with it. I just love the cartridge. But curious as the bigger boys too. :)

And actually someone once ran the calc for me:

Lapua 300prc brass: 100/$180. That's $1.80 each,
6th firing is $0.27 each.
CCI LRM primers are 1000/$80 so $0.08 each.
220gr Berger bullets are ~100/$80, so $0.80 each.
H1000 powder $55/Ib (if bought in 1lb quantities),
7000 grains/78grains = 89 reloads = $0.62 each.
So brass: 0.27 Primer: 0.08 Bullet: 0.80 Powder: 0.62 = $1.77 per round.
 
Rocketmandb said:
When Tumey opens again (still closed), I'll talk through my thought process on the 37XC and why, if I were to do it all over again, I'd go with a 338 AI first.
Click to expand...
Deal! I’m curious bw the 33xc, 338 AI, 33 EnAbler, 300 Norma (though Josh at PVA has talked out of the Norma).
 
category_theory said:
Deal! I’m curious bw the 33xc, 338 AI, 33 EnAbler, 300 Norma (though Josh at PVA has talked out of the Norma).
Click to expand...
Yeah, a 300 Norma is still the same class as the 300 PRC, just with more behind it. You won't pick up enough over a 300 PRC to justify a whole new rifle.

The 338 AI is interesting to me because:

- A little more umph than a 338 LM
- Can shoot the Berger 300s at a good velocity
- Lapua brass
- A relatively standard sized case length (as opposed to the XC cartridges)
 
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Rocketmandb said:
Yeah, a 300 Norma is still the same class as the 300 PRC, just with more behind it. You won't pick up enough over a 300 PRC to justify a whole new rifle.

The 338 AI is interesting to me because:

- A little more umph than a 338 LM
- Can shoot the Berger 300s at a good velocity
- Lapua brass
- A relatively standard sized case length (as opposed to the XC cartridges)
Click to expand...
They are also generally throated longer to allow for the longer, higher BC bullets too, no?
 
I wonder how close a throated 300wm would compare to a 300 prc. Same bullet, powder and barrel length.
 
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